I did a solo night hike last weekend. I climbed starting around sunset on October 5th, 2013. The forecast on this site had showed the minimum temperature at the peak to be 7C overnight and clear skies. When I reached the peak about an hour before midnight the fog was so thick that visibility was less than 5 feet. It was difficult just to find the buildings. Then the temperature began to drop and the wind picked up. In the morning when I woke up my water bottles had frozen inside my pack that I was sitting against. It would take temperatures around -5C to do this, much colder than 7C. So please be careful and prepared that the summit of the mountain can be much colder, wetter, and windier than this websites suggests.

But with that said the sunrise was beautiful and well worth the danger and discomfort of spending the night at the top. I would go again in much worse conditions.